<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
<div id="app">
    <div class="defaultClass" v-bind:class="classObject">Hello !</div>
</div>
</body>
<script src="../../js/vue.js"></script>
<script>
    var vm = new Vue({
        el: '#app',
        data: {
            classObject: {
                show: true,
                'text-danger': false
            }
        },
    })
</script>
</html>
